Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering最新文献

{"title":"Dialysis membranes for blood purification.","authors":"K Sakai","doi":"10.1163/15685570052061973","DOIUrl":"https://doi.org/10.1163/15685570052061973","url":null,"abstract":"All of the artificial membranes in industrial use, such as a reverse-osmosis membrane, dialysis membrane, ultrafiltration membrane, microfiltration membrane and gas separation membrane, also have therapeutic applications. The most commonly used artificial organ is the artificial kidney, a machine that performs treatment known as hemodialysis. This process cleanses the body of a patient with renal failure by dialysis and filtration, simple physicochemical processes. Hemodialysis membranes are used to remove accumulated uremic toxins, excess ions and water from the patient via the dialysate, and to supply (deficit) insufficient ions from the dialysate. Dialysis membranes used clinically in the treatment of patients with renal failure account for by far the largest volume of membranes used worldwide; more than 70 million square meters are used a year. Almost all dialyzers now in use are of the hollow-fiber type. A hollow-fiber dialyzer contains a bundle of approximately 10000 hollow fibers, each with an inner diameter of about 200 microm when wet. The membrane thickness is about 20-45 microm, and the length is 160-250 mm. The walls of the hollow fibers function as the dialysis membrane. Various materials, including cellulose-based materials and synthetic polymers, are used for dialysis membranes. This paper reviews blood purification, hemodialysis and dialysis membranes.","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"10 2","pages":"117-29"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/15685570052061973","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21740042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three methods for investigating, assessing and supporting the normal and pathological gait and manipulation activity.","authors":"A Morecki,&nbsp;J Oderfeld,&nbsp;T Zielińska,&nbsp;M Weiss,&nbsp;J Kiwerski,&nbsp;R Paśniczek,&nbsp;K Jaworek","doi":"10.1163/15685570052062684","DOIUrl":"https://doi.org/10.1163/15685570052062684","url":null,"abstract":"<p><p>Three methods to describe biped locomotion as well as manipulation activity are presented. Methods using so-called couple oscillators as rhythm generators are described. Based on a mathematical model, results of computer simulation of biped locomotion are presented. An indices method of assessing human gait for both normal and pathological cases was proposed and tested. The results showed that it is relatively easy to distinguish different gaits by using this method. This method was tested in clinical conditions. The third method deals with the problem of supporting the lost function of prehension movements. Implanted stimulators on the nerves combined with external orthoses were used. The clinical results show that these methods have practical advantages.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"10 3","pages":"199-212"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/15685570052062684","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21846643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computer-aided generation of stimulation data and model identification for functional electrical stimulation (FES) control of lower extremities.","authors":"G M Eom,&nbsp;T Watanabe,&nbsp;R Futami,&nbsp;N Hoshimiy,&nbsp;Y Handa","doi":"10.1163/15685570052062693","DOIUrl":"https://doi.org/10.1163/15685570052062693","url":null,"abstract":"<p><p>Standard stimulation data for unassisted standing up of paraplegic patients was generated by dynamic optimization linked with model simulation, to overcome the difficulties in the present electromyogram (EMG)-based method. The generated stimulation data were roughly in agreement with the normal subjects' EMG. From these, it is suggested that the 'model-based' method is useful as an alternative of the 'EMG-based method'. The same technique can be applied to generation of patient-specific stimulation data once the musculoskeletal system of a patient is properly identified. The musculoskeletal system must be identified from data taken from simple and noninvasive experiments for the identification method to be practically acceptable. We developed a musculoskeletal model and systematic identification protocols for this purpose. They were validated for the vastus lateralis muscle at the knee joint. The identification was successful and the predicted joint angle trajectories closely matched the experimental data. This implies that the model-based generation of patient-specific stimulation data is possible.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"10 3","pages":"213-31"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/15685570052062693","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21846644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fiber-optic measurement system of light scattering to evaluate embryo viability: model experiment using a latex sphere suspension and mouse embryos.","authors":"H Itoh,&nbsp;T Arai,&nbsp;M Kikuchi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In this study, we tested the efficacy of a fiber-optic light scattering system developed by us to measure mitochondrial size and particle density in embryos in order to establish a non-invasive method of evaluating human embryo viability for in vitro fertilization and embryo transfer. Particle size was determined by comparing the measured angular distribution of the light scattering intensity with that of the theoretical distribution using a 1.0 micron latex sphere suspension and mouse embryos. The measured light scattering pattern of the latex suspension was found to agree closely with the theoretically derived pattern. The measured light scattering pattern of the mouse embryo was similar to the calculated pattern of spheres, the diameter of which was equivalent to that of the mitochondria. Therefore, the measured light scattering is thought to be derived mainly from the mitochondria in the embryo. The relationship between light scattering intensity and latex particle density was also examined in order to estimate the detectable range of mitochondrial particle density. Since the detectable range of the particle density obtained in our study (1.4 x 10(6) - 1.4 x 10(11) particles/ml) was greater than the known mitochondrial particle density in human embryos (1.0 x 10(9) - 1.0 x 10(11) particles/ml), we believe that this mitochondrial particle density can be measured using our system. We concluded that it is possible to use our simple system as a non-invasive method for evaluating human embryo viability.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 2","pages":"101-11"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21314657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of intracranial pressure on the pial microcirculation in rats studied by a fiber-optic laser-Doppler anemometer microscope.","authors":"J Seki,&nbsp;Y Sasaki,&nbsp;T Oyama,&nbsp;J Yamamoto","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The fiber-optic laser-Doppler anemometer microscope (FLDAM) developed in our laboratory was applied to measure red cell velocity in individual pial microvessels in rats to determine the effect of intracranial pressure (ICP) on the pial microcirculation. The red cell velocity and the vessel diameter of pial microvessels were measured through a closed cranial window at controlled values of ICP between 0 and 50 mmHg. As ICP increased from 0 to 50 mmHg, the average relative diameter of venules with respect to the diameter at an ICP of 5 mmHg decreased from 1.18 +/- 0.12 (mean +/- SD) to 0.74 +/- 0.08 and the average relative velocity increased from 0.80 +/- 0.20 to 1.83 +/- 0.42 monotonically. The changes in diameter and velocity of arterioles with ICP were small, and they were not significantly different from those values at an ICP of 5 mmHg except for the diameter at an ICP of 20 mmHg. The mean volume flow rates calculated assuming a circular vessel cross-section did not show any statistically significant change with ICP between 0 and 50 mmHg in both arterioles and venules, which supports the concept of autoregulation.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 2","pages":"113-21"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21315181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of local anesthetics on red blood cell deformability.","authors":"S Ramakrishnan,&nbsp;H Schmid-Schönbein","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The deformability of human red blood cells under the influence of local anesthetics is studied in vitro. Red blood cells obtained from blood samples of healthy adult volunteers are treated with two local anaesthetics, procain and tetracaine, at varied concentrations. Deformability of red blood cells, in terms of its elongation index, were then examined by laser light shear stress diffractometer both at low and high shear forces. Results show that the deformability of local anesthetic-treated red blood cells is decreased when compared to that of control samples. At low shear forces and at low concentrations of the anesthetic agent, the decrease in deformability is not significant, whereas it is significant for high shear forces and at high concentrations. These effects are similar for both anesthetic agents studied.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 4","pages":"331-6"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21570424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of the conduction velocity distribution of peripheral nerve trunks.","authors":"Y Tu,&nbsp;S Honda,&nbsp;Y Tomita","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The distribution of the conduction velocity (DCV) of peripheral nerve fibers was estimated from two compound action potentials (CAPs) that were evoked at two sites by electrical stimulation and recorded at a different site. In this paper, a regularized least-squares method with a smoothness constraint and self-adaptation of the regularization parameter was adopted. Computer simulation showed it to be effective, especially for noisy CAP signals. In addition, the conduction lengths of nerve fibers were automatically determined by a Fibonacci search, since the conduction lengths of nerve fibers could not be measured accurately due to slack in fibers or changes in length associated with the contraction of adjacent muscles.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 3","pages":"189-97"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21470982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomimetic myoelectric hand with voluntary control of finger angle and compliance.","authors":"R Okuno,&nbsp;K Akazawa,&nbsp;M Yoshida","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of this study was to develop a new type of myoelectrically controlled biomimetic prosthetic hand which has almost the same dynamics as that of the neuromuscular control system of the finger muscles, and in mechanical properties of the muscles and of the stretch reflex. One of the characteristic features of the neuromuscular control system in man is the increase in the compliance around the joint with decreasing activity of the muscle. Our prosthetic hand consisted of two surface EMG signal processing units, a digital servo system for a DC motor and 1 d.o.f. mechanical hand with three fingers. The dynamics of the neuromuscular control system including variation of the compliance around the joint was realized by using a position control system of the finger movement, force feedback and a variable gain which was modulated by the amplitude of IEMGs (rectified and smoothed EMG signals). EMG signals recorded from a pair of antagonistic muscles used to flex or to extend the wrist were used as control signals. It was shown that the finger angle and the compliance of the prosthetic hand could be controlled voluntarily with EMG signals, and that an amputee could grasp a soft object easily with the prosthetic hand. Utility of the biomimetic prosthetic hand was shown by executing myoelectric control experiments in one healthy subject and one amputee.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 3","pages":"199-210"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21470983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress analysis in three-dimensional foot models of normal and diabetic neuropathy.","authors":"S Jacob,&nbsp;M K Patil","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In this paper, a three-dimensional two-arch model of the foot is developed, taking foot geometry from X-rays of normal and diabetic subjects, which considered bones, cartilages, ligaments, important muscle forces and foot-sole soft-tissue. The stress analysis is carried out by a finite element technique using NISA software for the foot models simulating quasi-static walking phases of heel-strike, mid-stance and push-off. The analysis shows that the highest stresses occur during the push-off phase in the dorsal central part of the lateral and medial metatarsals and the dorsal junction of the calcaneus and cuboid. The vertical stresses, in the foot-sole soft-tissue at the foot-ground interface, for normal and diabetic neuropathic subjects, are the highest in the push-off phase and were in good agreement with the experimentally measured foot pressures. It is found that the foot-sole vertical stresses (at the foot-ground interface), in diabetic neuropathy, increase considerably in the heel region in the heel-strike phase and in the fore-foot regions in the push-off phase. The high stress concentration areas, in the plantar surfaces indicated above, are of great importance since it is found from clinical reports that in diabetic neuropathic patients these areas of the foot-sole are prone to ulcers. Thus, this investigation could possibly provide information on the areas of high stress concentration of the foot bones in the normal foot giving rise to arthritis when the mechanical strength decreases and possible high stress regions of foot bone giving rise to disintegration of tarsal bones in leprosy, as well as an insight into the factors contributing to plantar ulcers in diabetic neuropathy.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 3","pages":"211-27"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21470984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliability of measurement of muscle fiber conduction velocity using surface EMG.","authors":"M I Harba,&nbsp;L Y Teng","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Cross-correlating two surface EMG signals detected at two different locations along the path of flow of action potential enables the measurement of the muscle fiber average conduction velocity in those active motor units monitored by the electrodes. The position of the peak of the cross-correlation function is the time delay between the two signals and hence the velocity may be deduced. The estimated velocity using this technique has been observed previously to depend on the location of the electrodes on the muscle surface. Different locations produced different estimates. In this paper we present a measurement system, analyze its inherent inaccuracies and use it for the purpose of investigating the reliability of measurement of conduction velocity from surface EMG. This system utilizes EMG signals detected at a number of locations on the biceps brachii, when under light tension, to look for any pattern of variations of velocity as a function of location and time. It consists of a multi-electrode unit and a set of eight parallel on-line correlators. The electrode unit and the parallel correlators ensure that these measurements are carried out under the same physical and physiological conditions of the muscle. Further, the same detected signals are used in different measurement configurations to try to understand the reasons behind the observed variations in the estimated velocity. The results obtained seem to suggest that there will always be an unpredictable random component superimposed on the estimated velocity, giving rise to differences between estimates at different locations and differences in estimates with time at the same location. Many factors contribute to this random component, such as the non-homogeneous medium between the muscle fibers and the electrodes, the non-parallel geometry and non-uniform conduction velocity of the fibers, and the physical and physiological conditions of the muscle. While it is not possible to remove this random component completely from the measurement, the user must be aware of its presence and how to reduce its effects.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"9 1","pages":"31-47"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21223463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}